Power transmission assembly



ug. 20, 1940. A Kul-INS ET AL 2,211,832

POWER TRANSMIS S ION AS SEMBLY Original Filed June 4, 1937 y Jy-5- Patented Aug. 20, 194) PATENT OFFICE POWER TRANSMISSION ASSEMBLY Austin Kuhns and Emil R. Gasser, Buffalo, N. Y.,

assignors to Panel-Birmingham Company, Incorporated, Buffalo, N. Y., a corporation of Connecticut Original application June 4, 1937, Serial No.

Divided and this application February t72.6, 1938, Serial No. 192,736

1 Claim.

Our invention relates to power transmission assembly adapted particularly for use in driving or propulsion systems in which power units such as Diesel engines yare connected through hydraulic clutch mechanisms and gearing elements with an `element to be driven, as for example the propeller of marine craft, and this application is a division of our copending application Serial No. 146,448 filed June 4, 19.37.

In propulsion systems of this type it has been found desirable to utilize gearing of the double helical or herringbone type-on account of its more efficient and noiseless operation. In this type of system, as for example a marine propulsion system, the propeller shaft drive gear is journalled in thrust bearing structure which tends to prevent axial shift or oscillation of the propeller shaft but such oscillation may take place, particularly when the propeller has its direction of rotation changed. Where this propeller gear'and the driving pinion driven by the engine are of the double helical or herringbone type, any relative axial displacement of the gears While in operation would cause friction between teeth and grinding and wear thereof besides causing considerable noise, and means must therefore be provided to prevent any such relative axial displacement as would disturb the proper and efficient meshing of the gear elements. An important ob-v ject of our invention is therefore to provide arrangement which will permit the driving pinion to freely move with the driven gear so that proper mesh is at all times maintained, and this we accomplish by mounting the clutch and driving gear element of each drivingunit assembly in bearings in which it may freely shift axially as a unit a sufficient distance for the driving pinion to follow any axial shifting of the propeller shaft and gear, the engine shafts and their coupling connections with the transmission unit assemblies have lng usually enough freedom of movement to permit .such comparatively small axial shifting of the transmission unit assembly as will be suiiicient for movement of the drive pinion with any axial shift that the propeller shaft and its gear may be submitted to. Our invention may be used advantageously in power transmission assemblies such as disclosed in our copending application referred to and in which the structure for taking up the axial thrust of the clutch elements is selfcontained or inherent in the clutch structure and its shafting.

The various features of our invention are incorporate'd in the structure disclosed on the drawing, in which:

(Cl. I4-189.5)

Figure 1 is a more or less ldiagrammatic plan view showing a propulsion system; and

Figure 2 is an enlarged vertical diametral section through one of the transmission assembly units.

Referring to Figure l which shows a marine propulsion system, each driving unit comprises an engine E whose shaft is' connected by suitable clutch means'IIl with the shaft II which carries the impeller member I of a hydraulic clutch, the supporting shaft structure I2 for the runner element R of the clutch carrying a drive pinion I3, the drive pinionsof the two driving units meshing with a gear I 4 on a shaft I5 which is connected by suitable coupling means I 6 with the shaft Il carrying a propeller I8, the gear elements being of the double helical or herringbone type.

Referring to Figure 2, the impeller shaft II is journalled in a bearing structure I9 supported on the framework or base structure 20, the shaft terminating at its inner end in a head 2I to which the impeller element I of the clutch is bolted. The runner shaft I2 is journalled at its end in suitable bearing structures 22 and 23 supported by the frame work 20, the shaft at its inner end having the flange 2 4 to which the runner element R of the clutch is bolted. A cover structure 25 is secured at its periphery to the runner element and extends around the impeller element and surrounds the head 2| of the impeller shaft II, o

this cover structure serving to retain the hydraulic fluid within the clutch elements.

The runner shaft I2 is hollow'or tubular, and intermediate the bearings 22 and 23 the shaft is .enlarged to form the drive pinion I3, vthere being suflicient clearance between the bearings 22, 23, and the ends of the pinion and sufficient clearance between the shaft head 2| and the bearing I9 for axial reciprocation of the shaft structure and the clutch structure as a unit.

'Ihe hollow shaft I 2 has the outer end portion 26 of reduced diameter to leave a shoulder 2l and to provide a seat for the inner ring 28 of a ball bearing structure whose outer ring 29 seats in a cylindrical retainer cup 30, the bearing balls 3i being interposed between the rings, the inner ring 28 abutting the shoulder 21.

Extending into the outer end of the shaft I2 through the reduced end 26 is a tubular link 32 whose base has the passageway 33 for receiving the outer end of a rod or bar 34 which extends inwardly through the shaft and at its inner end is secured to the propeller shaft II, axiallyV thereof, by threading into the bore 35 in the shaft,

a stop collar or flange 36 being provided 0n the.

rod to abut the shaft end after the rod has been securely threaded into the bore.

Near its outer end, the rod has the flange 31 i abutting the inner end of the link 32, the end f the rod within the link being threaded to receive a nut 38 between which and the flange 31 the base of the link is securely clamped.

Near its outer end, the tubular link 32 has the radially extending circular web 39 engaging the outer end of the cup 30, the web having the annular flange 40 for engaging in the cup to abut the outer bearing ring 29. The rod 34 is of such length that when the nut 38 is tightened and the link 32 drawn inwardly, the link web 39 will shift the ball bearing structure inwardly, and as this structure abuts the shoulder 21 on the shaft I2, the shaft and the runner element R of the clutch will be shifted inwardly, this adjustment determining the proper gap between the impeller and runner elements, and the ball bearing structure, which is anchored to the shaft II through the link 32 and rod 34, taking up the thrust as the impeller and runner elements tend to axially separate under the pressure of the hydraulic fluid when the assembly is in operation. The thrust take-up structure is thus an inherent part of the clutch and shafting structure and is contained within the shafting and the clutch structure. The ball bearings permit easy relative rotation of the impeller and runner elements of the clutch due to the slippage of the runner element.

A housing 4I encloses the ball bearings and the end of the link structure 32, and this housing is closed by a cover 42. The cover supports a bracket 43 through which and the cover extends the passage 44 for the inlet of hydraulic fluid for supplying the clutch structure. 'Ihe cover has the annular recess 45 surrounding the inner end of the passageway 44 into which recess the outer end of the link 32 extends to form a sealed joint so that the hydraulic fluid charged into the passage 44 cannot escape from the link 32 into and through which the uid flows and from which it flows to the interior of the shaft I2 through a number of passageways 46 in the link wall, the fluid flowing from the inner end of the shaft I2 into the impeller and runner elements.

Referring to Figure 1, the gear shaft I as shown is journalled in a thrust bearing which would tend to prevent axial shift or oscillation of the shaft. However, there may be more or less axial oscillation, particularly when the direction of rotation of the propeller is changed. Where the gearing is of the herringbone type,

provision must be made to permit axial movement of the drive pinion I3 with the gear in order to prevent undue pressure between the gear teeth and grinding or wear thereof and also to prevent noisy operation. With our arrangement in which the shaiting for the clutch impeller and runner elements is free for axial shift in the bearing structures I9, 22, and 23, the clutch structure and the shaft structures are movable as a unit axially so that the drive pinions may readily follow any axial shifting of the propeller shaft and gear and so that proper meshing engagement is at all times assured. During such reciprocation of the clutch and shafting structure, the outer end of the link 32 shifts in the recess 45 while still maintaining a sealed joint for preventing escape of hydraulic fluid.

rIhe clutch structure is protected by a casing 41 which serves also as an oil reservoir or sump. and the gearing elements are enclosed within a casing 48, the casings being fixed and suitably supported by the base structure 20.

We thus provide simple yet eflicient structure and arrangement for enabling the drive pinionsA to readily follow axial movement of the propel- 1er gear. We do not, however, desire to be limited to 'the exact construction and arrangement shown and described, as changes and modifications may be made without departing from the scope and spirit of the invention.

We claim as follows:

A shaft for connection to a load such as a propeller, a thrust bearing for said shaft tending to hold said shaft against axial displacement, a herringbone gear on said shaft, a herringbone driving pinion meshed with said gear, spaced stationary bearings, a unitary structure including said pinion mounted for limited axial movement as a unit in said bearings to enable said pinion to follow axial displacement of said gear under changing load torque conditions, said unitary structure comprising a hydraulic coupling structure having an impeller element and a runner element in axially opposed relation, a drive shaft connected to the impeller element and journaled in one of said bearings, a transmission shaft connected to said runner element and disposed in axial alignment with said drive shaft and journaled in the other of said stationary bearings, said pinion being secured to said transmission shaft, and means including means in said transmission shaft coupling said transmission shaft and said driving shaft in assembled relation.

AUSTIN KUHNS. EMIL R. GASSER.. 

